1. Field of the Invention
This invention relates to a high velocity fan of the type which has open front and rear grills, with a pre-assembled fan motor cover assembly fastened to the fan's rear grill.
2. Description of the Prior Art
High velocity fans are in widespread use, and are generally constructed with open front and rear grills with the motor fan assembly mounted to the rear grill. These fans are sold at low prices and there is considerable competition in the marketplace. In order to be competitive, the costs of constructing the fans must be kept as low as possible, which is difficult as the assembly of the fans, which is usually accomplished by unskilled labor, is labor intensive due to the number of components and the sequence of assembly. For example, in a typical fan in order to assemble the motor to the rear grill the following steps are required:
Plug motor leads into switch. PA1 Plug cord set leads into switch. PA1 Wire motor ground wire to cord set ground wire with wire nut. PA1 Feed cord set and switch through rear grill and align motor mounting bolts with rear grill motor support. PA1 Using (4) hex nuts, attach motor to rear grill. PA1 Position switch inside motor cover. PA1 Using a screw, attach the switch to the cover. PA1 Position motor cover against rear grill so that mounting holes align. PA1 Using (3) screws, attach motor cover to rear grill. PA1 Using glue, attach name plate to motor cover. PA1 Using glue, attach switch plate to motor cover. PA1 Affix switch knob to switch stem. PA1 Test fan operation.
The listed steps also require that the assembler work from both sides of the fan grill and in tight places.
The complexity of the steps leaves considerable room for error, and the resultant product may have an unfinished appearance and be subject to problems due to the structure of the product.
The assembly of the high velocity fan of the invention requires the assembler to place the pre-assembled fan motor cover assembly in a holding fixture, position the rear grill plate in line with locating studs from the fan motor cover assembly, and insert and activate three blind rivets.